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CTI Blog - Why Build In Wood?

This article is by Paul Brannen, MEP for the North East England Region. It originally appeared on www.northeastlabour.eu

Historically timber has been used to build homes, especially one and two storey buildings. Taller and larger buildings have been possible with timber frames but above 5 or 6 storeys is rare.

However, relatively new engineered timber products such as Cross Laminated Timber (CLT) and Laminated Veneered Timber (LVL) have the structural strength of steel and concrete, enabling wooden framed buildings to now be built to much taller heights and on a much larger scale.

These new products have enabled the construction of the world’s tallest wooden building, Tallwood House at Brock Commons East, on the campus of the University of British Columbia in Vancouver, Canada. It is 53m tall with 18 floors - you can watch it being constructed in under 3 minutes here.

Wooden buildings even taller than this are currently under construction including the HoHo building in Vienna, Austria which will have 24 floors, see here, and a Japanese company are planning on building the world’s tallest wooden skyscraper. Other wooden skyscrapers are being built or are planned across the globe.

There are many benefits to be gained from building in engineered wood, including:

Speed

Building in wood can see a floor a week being constructed on site, as the wooden panels are constructed off site in factory conditions. This is twice as fast as concrete. Overall wooden buildings can be up to a third faster to build reducing construction site costs i.e. the hired crane is there for less time.

Sustainable

Timber is a renewable and sustainable product when managed and produced in an environmentally friendly way. Construction timbers, such as CLT, LVL and Glulam, are made with a non-toxic adhesive and can be made with little or no burning of fossil fuels unlike steel, brick and block which all need large amounts of heat to produce and they tend to derive this heat from the energy produced from burning fossil fuels. The actual chemistry involved in making cement for concrete results in large amounts of CO2 being released. Theoretically this could be captured (Carbon Capture and Storage - CCS) but to date it has not happened.

Sequestration of Carbon

While trees are growing they sequestrate carbon from the air. In fact trees could rightly be described as CCS ´machines´. When trees are turned into timber products the timber still continues to sequestrate the carbon for the life time of the wooden product, hence timber is a natural “carbon sink”.

Tall and/or large steel and concrete buildings have large carbon footprints. Comparable wooden buildings can have a reduced carbon footprint of 60-75% in comparison.

The importance of substituting for steel and concrete

Concrete and steel have large carbon footprints. One of the primary ingredients in concrete is cement and to make cement you need to heat and grind up limestone or a similar material. In addition to the energy required in the manufacturing process, the U.N calculate approximately 1 ton of carbon dioxide is emitted per ton of cement produced. As concrete is the second-most consumed substance on the planet, after water, cement production accounts for as much as 8 percent of human-produced carbon dioxide emissions.

Concrete and steel are both heavy to transport involving large numbers of lorries that in turn generate exhaust fumes that contribute to poor air quality especially in our cities and they also burn fossil fuels exacerbating climate change.

Wooden buildings can be five times lighter than a steel and concrete equivalent meaning transport costs both financially and environmentally are reduced. Lorry deliveries to the construction sites where wood is the principal building material can be reduced by 80% because wood is lighter and needs fewer lorries to move it. As wood is lighter this can also reduce the groundwork (foundation) costs.

A 125m high building made from wood could have a 75% lower carbon footprint than one made from steel and concrete.

50% less energy is used to manufacture wooden rather than concrete buildings and only 1% of the energy needed to produce steel.

During construction wooden buildings produce less dust and their construction is quieter, which is good news in urban areas.

Following construction in cold climates the estimated energy consumption and carbon emissions for CLT buildings are 9.9% and 13.2% lower than those of reinforced concrete buildings in view of life-cycle assessment; see here for more information.

Currently using building methods centered around, concrete, steel, brick and block, the building sector is responsible for 42% of final energy consumption, 35% of total greenhouse gas emissions, 50% of extracted materials and 30% of water consumption in the European Union. Construction and housing have a fundamental role to play in enhancing societal goals for sustainable growth, see here.

Health/Ambiance

- improvements to a person’s emotional state and level of self-expression

- improved air quality through humidity moderation.

Renovation and Refurbishment

As a light-weighted material that can be processed easily, wood is the ideal material for renovation and refurbishment, allowing high flexibility for inhabitants and users to adjust buildings to specific needs.

Cost; Timber/CLT v concrete/block/steel

A question often posed is whether building in wood is cheaper than building in a material such as concrete. To help answer this question, Building magazine undertook a price comparison in June 2017 and noted:

“We have prepared two detailed cost models, one each for a CLT and concrete design for a seven-storey private residential building. The scheme has been designed with both a timber and concrete solution in mind at the outset, with a structural layout to suit both.

“…the construction cost variance between timber and concrete for this hypothetical scheme is minimal. The higher CLT superstructure costs are offset by the ability to reduce pile quantities because of a lighter frame, hence a saving on substructure. The CLT programme for the frame and upper floors is around 10–15% shorter than the concrete option, resulting in a lower preliminaries cost.”

The cost of wooden buildings can be kept down by pre-fabricating panel sections in factory conditions where they can be made to the millimetre, meaning that there’s little to no waste. Doors and window apertures can be pre-cut in the factory. Government figures show about a third of the materials that arrive on a construction site using concrete tend to get sent to landfill resulting in more lorries on the road.

In April 2018 Alinea Consulting produced an influential report that highlighted the advantages of using CLT over concrete. The report, Residential Timber: Cost Model, suggests CLT is a viable alternative and uses two detailed exemplar cost models to demonstrate the point.

Wooden buildings are more energy efficient meaning longer term the owners will both use less energy and pay smaller energy bills. If the CLT used is thick enough then an energy saving of 14% could occur. This is because wood has a natural thermal efficiency which means timber systems can be more cost effective in constructing energy efficient buildings than concrete, block or bricks.

Additionally, In a recent (July 2018) independent study produced by Rider Levett Bucknall (rlb.com) a comparison was made between the cost of timber frame v masonry build methods in order to determine which is more economical for affordable housing. The study found "the overall situation ... results in the timber frame solution being more economical to construct" p16. It was also "quicker".

Fire

But aren’t wooden buildings more prone to hazards and natural disasters?

Buildings made from CLT have no inherent fire risk. When brought into contact with fire the outer surface of the wood chars and then acts as a very effective insulator for the wood below. When the heat source is removed the fire goes out. Furthermore, CLT remains more structurally stable when subjected to high temperatures.

See demonstration of an attempt to set fire to CLT with a blow torch in this Economist video on wooden skyscrapers here.

Further, Silvia Melegari wrote in Revolve that CLT buildings, “have the flexibility to handle the world’s strongest earthquakes with no loss of life or structural change”.

CTI Blog - The 4 wonders of the timber industry

This guest blog post is by Andrzej Manka, Sales Manager at Timber Expo.

When we think of innovative sectors, the timber industry probably isn’t the first that springs to mind. Many believe this industry is very traditional, conservative and reluctant to change.

In a word - die-hard! This is especially true when you compare it with other industries: new tech or finance for example, not to mention AI. In our ultra-modern world, we appreciate constant growth, astonishing productivity and impressive innovation above all else.

But this stereotype doesn’t match with the reality; the timber industry is now up there at the top of UK and international innovation lists. Admittedly, these represent only a small minority of timber companies, but their success gives the industry dynamics and makes it the leading power in the whole construction business.

As Daniel Kahneman states in his brilliant book “Thinking, Fast and Slow”, stereotypical and simplified thinking is a characteristic for the “Fast system” of thinking, the type we use to understand something immediately and without any unnecessary effort. This way of thinking and making sense of the world evoke an image of the timber industry as rather backward, and poor in innovation. However, there is a second way of thinking, the “Slow system,” which enables us to go through all important details and deal with the more complex issues.

When you take the time to study the timber industry, as I have been doing for the past 11 months, you will discover so many astonishing and innovative projects in the industry that you’ll likely fall in love in timber quite easily. Not to mention that wood is beautiful, and makes our homes and offices so much more aesthetic, natural and trendy.

The value of the timber industry to the British economy is £7 billion.

So let’s have a look at the four wonders of the timber industry. They are not really “wonders” in a literal sense; they are actually the result of creative, courageous and hard working timber specialists. This is, of course, a very subjective (dare I say even controversial?) list of “Four wonders.” It’s more like an invitation for us to discuss certain achievements in the timber industry.

One other thing- this list list contains different categories like technology, production, and architecture. Maybe it’s a bit risky to compare projects that belong to different science or business activities, but let’s try.

1. Transparent wood

Invented first in 1992 by German researcher Siegfried Fink and then, independently developed by Professor Lars Berglund. This Swedish KTH research group, led by Professor Liangbing Hu from The University of Maryland, have elaborated a method to remove the color and some chemicals from wood. Thanks to that, the wood becomes 90% transparent. Potential application of this invention is very far-reaching and the wood could be used in construction, interior design and even the car industry.

2. Engineered wood

On the image above you can see an example Cross-laminated-timber housing in east London; “a 10-storey carbon-neutral apartment complex in London's Dalston, the "world's largest cross-laminated timber building".

Engineered wood technologies are what makes the timber & construction industry so dynamically developing and profitable. The most used in the construction industry are plywood, fibreboard, cross-laminated timber (CLT), laminated strand lumber, and many more. Because of the use of these timber products, it’s been predicted many times during the last decade that timber will be the main building material in XXI century.

3. Timber skyscrapers

At the moment, the world’s tallest timber building is a 14-storey apartment block in Bergen, Norway. However, we are expecting a lot of new timber skyscrapers in the UK, USA, Europe and Asia in future. One of the advanced projects that should be started very soon is an 80-storey, 300m high wooden building integrated within the Barbican (on the image above). Around 1,000 new flats will be build in this impressive 93,000-square-metre timber skyscraper project.

Timber skyscrapers are not only stunning examples of strong “timber trends” in contemporary architecture, but they also bring sustainable development to big cities, as well as reducing carbon emissions.

4. Museum Globe of Science and Innovation

Are you familiar with the history of the Internet? If so, you’ll know that Tim Berners Lee invented the World Wide Web when he worked in The European Organization for Nuclear Research (CERN) based in Geneva, Switzerland. The same organization has built the Globe of Science and Innovation, a fine example of outstanding construction. The museum of modern technology, made of wood, is a perfect concept. It creates a very special atmosphere for those who wants to stop for a moment and contemplate the nature of technological innovation.

There are so many more impressive wooden wonders of the world! You can find literally hundreds of great examples. One of my favorites is The Splinter, a wooden sports car with a twin-supercharged 4.6 litre V8.

Not to mention an interesting initiative from Metsa, one of the world’s leading timber companies. They have just started the Open Source Wood initiative, a project to encourage innovation and the sharing of knowledge inside the timber industry. Metsä Wood’s Executive Vice President, Esa Kaikkonen, explains why the project was established: “Not enough knowledge about modular wood design and building is shared, so wood construction remains niche. There is plenty of innovation but it is difficult to find, so Open Source Wood is our solution. We believe that with open collaboration the industry can achieve significant growth.”

There is still many ways in which the timber industry can evolve, but there is no doubt that the timber revolution has already started and it looks very exciting!